LessLoss C-MARC & Firewall

High fidelity cables designed to extract the maximum detail from your system.

The world of audio is steeped in a strange duality. On one hand, nothing has changed in the last 50 years: vacuum tube amplification technology, driver and cabinet designs for loudspeakers, among other things. On the other hand, many things have changed: materials, the ability to simulate the results of applying different elements, and more. In this scenario of constant evolution, the Lithuanian firm LessLoss has established itself as one of the most unique and scientifically rigorous voices in signal and energy treatment.

Today at Et Sona, we explore the LessLoss C-MARC Classic Power, a cable that defies the industry's aesthetic conventions to focus on a fierce battle against electromagnetic noise. How does it achieve this? Through a sophisticated passive filtering structure that seeks to restore purity to the current powering our equipment.

Before beginning, I must thank Louis Motek from LessLoss Audio, not only for lending me the cables for testing but also for his recommendations and attentiveness throughout the process. One learns a lot from people like him, who have both experience and the desire to share their knowledge.

In the package sent by Louis, I received three C-MARC Classic Power cables and one Firewall 640x. After explaining my current system configuration, the recommendation was: C-MARC cable from the wall outlet to the Firewall, connecting it to the Lampizator Silk. Then, one of the C-MARC cables went to the Lampizator Atlantic 5 TRP. In this initial stage, there was an important warning: it is necessary to check the phase at the power connector and, at all costs, maintain it throughout the chain.

I will not go into technical details, but experienced audiophiles will already be aware of what this is about. Phase must be maintained in the system for best results; LessLoss makes the process somewhat easier by marking which side of the cables carries the current, or the "Live" side. Once the checks were completed at every link in the chain, I prepared to listen, and this is where the second recommendation came into play: the "Burn-In" process.

Yes, some of you may not believe in it. In my experience, I consider there to be some truth to it, more so in some elements than others, but follow the manufacturer's recommendations; it does no harm. In fact, it was exactly as described in a document that gathers the listening experiences of LessLoss and users of C-MARC cables, available here.

Experience dictates that during the first 1 to 3 days, the sound of the cable is not ideal. Some people have even reported comparatively poor sound on day 2. The second period, between days 3 and 10, is reported as a "roller coaster" effect where fluctuations inexplicably occur between good and non-ideal sound. Between 10 and 20 days, the sound tends to stabilize and reach its maximum potential. My experience? Similar, with a few nuances. It is true that "cold," the cables did not seem like much; I even re-verified the connection chain regarding the phase and, finding everything in order, waited to notice changes.

Around the second day, I noticed no improvement, but around the day 5 mark, something caught my attention.

Construction

C-MARC (Common Mode Auto-Rejection Concept) technology is based on a counter-propagating dual-helix geometry that naturally cancels induced noise. Unlike traditional cables with heavy shielding that often compress dynamics, LessLoss uses extremely fine Litz conductors, individually enameled and braided with a precision that borders on the obsessive.

However, the true heart of this version is the Entropic Process. As the brand describes, this treatment subjects the cable to conditioning that accelerates the maturation of the conductive material at a molecular level. It is a process that mimics years of intensive use but is performed in a controlled environment, eliminating internal stresses within the metal and allowing the signal to flow without the typical harshness of a "virgin" cable.

Physically, the cable is surprisingly light and flexible, covered by a black mesh that aids in mechanical damping. But beware: here, installation is critical. It is fundamental to respect the electrical phase at the power outlet. The C-MARC is so transparent that, if connected out of phase, the soundstage collapses and tonal coherence disappears. For this review, we have integrated the cable alongside the Firewall 640X filter, creating an impassable barrier against mains contamination.

The Firewall 640x, for its part, is a filtering system at a capillary level that does not use, according to the manufacturer, coils, diodes, or resistors. It is a proprietary system presented in a solid wood casing, designed to eliminate micro-vibrations. What is inside? Pure copper rods, coated in transparent resin and with the cable terminations securely soldered to the terminals of the IEC connector. By the way, the copper rods feature a gold-plated section, which creates a passive filtration system without the use of electronic components that degrade the signal. A very interesting approach and, in my experience, with good results.

How it sounds

As I described at the beginning of this entry, the burn-in process for these cables is an emotional roller coaster, perfectly documented by LessLoss in their official curve. After the first 24 hours of astounding clarity, the cable usually passes through a phase of "opacity" before finally stabilizing about a week to a week and a half after its application. Once this period was overcome in our system, the observations were revealing.

1. Ibrahim Maalouf – "Doubts" (Wind): With Maalouf’s trumpet, the C-MARC demonstrates an astounding capacity for cleanliness. The background of the recording, fed by the Lampizator Atlantic 5 and the McIntosh set, becomes blacker and deeper. The micro-dynamics of the musician's breath and the texture of the air passing through the instrument gain a physical presence that was previously blurred by background mains noise. Through the Axxess L1, any trace of harshness in the treble has been eliminated, even given the high resolution of the Kapton tweeters and their characteristic presentation in silent passages, revealing the slightest detail hidden in the silence.

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3. Woodkid – "Iron" (The Golden Age): This track is a trial by fire for power management. Massive percussion and epic brass demand instantaneous current delivery. Here, the C-MARC, supported by the Firewall 640X, allows the MC502 to strike with an authority that I had not encountered before. The separation between the layers of synthesizers and the string section is surgical. There is no compression; the dynamics expand naturally, allowing the track's climax to fill the room without a sense of effort. The authority with which the bass was resolved took me off guard and, I must admit, it had been a long time since I heard such definition in that region from the McIntosh, even making me fear the need to upgrade a component.

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5. London Grammar – "Hey Now" (If You Wait): Hannah Reid’s voice is the absolute center. The LessLoss cable seems to remove a layer of electronic "haze," letting the midrange breathe with an organic naturalness. The sub-bass that sustains the song appears with precise articulation, without artificially inflating the room but with an extension that reaches the floor. The phase coherence mentioned earlier translates here into a stereo image where the voice floats exactly at eye level, with a depth that breaks through the back wall of our listening room and greatly extends the recording's depth plane.

Technical Data

• Technology: C-MARC common-mode rejection via dual-helix geometry.

• Treatment: Entropic Process for molecular stabilization of the conductor.

• Conductors: High-purity enameled Litz copper with optimized cross-section.

• Dielectric: Natural fibers and lacquer, avoiding polymers that accumulate static charge.

• Flexibility: High, facilitating installation in complex racks like the Prestige 4.

• Associated Accessories: Joint use with Firewall 640X recommended for optimal results.

Conclusions

The LessLoss C-MARC Classic Power is a power cable developed with a rigorous process of trial and error. The point of its evolution and the studied reaction to each of its phases and processes are remarkable. What the C-MARC offers is not just a solid base for the equipment's power management, but an active implementation in the ability to reduce background noise. This, in turn, allows components of the caliber of the Lampizator Atlantic 5 TRP or the McIntosh C504 preamp to show their true face, freed from interferences and parasitic noises that, in attentive listening, can uncomfortably reveal themselves in the background of the music.

The set of C-MARC cables and the Firewall provide an interesting filtering system, as well as a physical platform for the elimination of physical vibrations that, in turn, can alter or harm the equipment's performance. Not to mention their attractive design and materials. They are quality products and, as such, pleasant to the touch and the eye, which is a definite plus.

It is vital to follow the manufacturer's recommendations: patience with the burn-in curve and scrupulous attention to electrical phase. When these elements align, the result is a transparency that redefines what we expected from our digital front end. At Et Sona, we are certain: if your system already possesses a significant level of resolution, the C-MARC is responsible for opening the last window that remained closed. It is Lithuanian engineering at the service of pure emotion.

LessLoss C-MARC cables and the Firewall 640x, as well as the rest of the brand's cables (interconnects, digital, etc.) and conditioners, are available on their website. By the way, I also recommend reading their specifications and construction details, as there is much to be learned there.

They can be used together or separately, and the great advantage of this modular approach is that it can grow with the user's needs and be built up little by little. Today a cable, tomorrow the firewall, the day after another cable, etc.

Given what I have seen and, above all, what I have heard, I do not hesitate to recommend LessLoss products to the Et Sona audience.

Gallery.